Examples with DefaultRepositorySelector org.apache.log4j.spi.DefaultRepositorySelector used on opensource projects

Example 1 with DefaultRepositorySelector

use of org.apache.log4j.spi.DefaultRepositorySelector in project ACS by ACS-Community.

the class Log4jFactory method enableAcsLogging.

/**
	 * This method must be called once in order to enable ACS logging behind the scenes of log4j logging.
	 * <p>
	 * The log4j framework is quite resistant against being substituted with a different logging framework.
	 * Even though it is possible to configure a custom logger factory using <code>log4j.loggerFactory</code>,
	 * that factory will not be used when 3rd party code calls the usual <code>Logger.getLogger(name)</code>.
	 * It seems to make sense only for cases where the custom logger is used as in <code>MyLogger.getLogger(name)</code>.
	 * log4j-over-slf4j (http://www.slf4j.org/legacy.html) simply re-implements the relevant log4j classes, 
	 * which is too much trouble here for us because only basic log4j features are being used. 
	 * <p>
	 * We make use of the RepositorySelector mechanism, which log4j foresees for a different purpose, 
	 * to separate logging contexts in an application server that does not have classloader separation.
	 * (See also http://articles.qos.ch/sc.html.) 
	 * It is not possible to configure this externally, so that an application must call this method.
	 * See also http://mail-archives.apache.org/mod_mbox/logging-log4j-user/200904.mbox/%3Ca44e15a30904020424g4b7d7fcx63ca32152c81f80d@mail.gmail.com%3E
	 * <p>
	 * @TODO: In the future we could let ClientLogManager call this method, 
	 * but currently we are afraid of side effects with frameworks other than the laser alarm system
	 * that also use log4j (see http://jira.alma.cl/browse/COMP-8423).
	 */
public static void enableAcsLogging() {
    System.setProperty("log4j.defaultInitOverride", "true");
    //		System.setProperty("log4j.debug", "true");
    Hierarchy h = new MyLog4jHierarchy();
    RepositorySelector repositorySelector = new DefaultRepositorySelector(h);
    LogManager.setRepositorySelector(repositorySelector, null);
    Logger rootLogger = Logger.getRootLogger();
    rootLogger.removeAllAppenders();
    // to avoid "log4j:WARN No appenders could be found for logger (root)."
    rootLogger.addAppender(new NullAppender());
    rootLogger.setLevel(Level.ALL);
}

Example 2 with DefaultRepositorySelector

use of org.apache.log4j.spi.DefaultRepositorySelector in project scheduling by ow2-proactive.

the class Log4JRemover method removeLogger.

public static void removeLogger(String name, Hierarchy hierarchy) {
    try {
        Hierarchy usedHierarchy;
        if (hierarchy == null) {
            Field repositorySelectorField = LogManager.class.getDeclaredField("repositorySelector");
            repositorySelectorField.setAccessible(true);
            DefaultRepositorySelector selector = (DefaultRepositorySelector) repositorySelectorField.get(null);
            Field repositoryField = DefaultRepositorySelector.class.getDeclaredField("repository");
            repositoryField.setAccessible(true);
            usedHierarchy = (Hierarchy) repositoryField.get(selector);
        } else {
            usedHierarchy = hierarchy;
        }
        Field htField = Hierarchy.class.getDeclaredField("ht");
        htField.setAccessible(true);
        Hashtable ht = (Hashtable) htField.get(usedHierarchy);
        Class categoryKeyclazz = Class.forName("org.apache.log4j.CategoryKey");
        Constructor<?> categoryKeyConstructor = categoryKeyclazz.getDeclaredConstructor(String.class);
        categoryKeyConstructor.setAccessible(true);
        Object key = categoryKeyConstructor.newInstance(name);
        Logger logger;
        synchronized (ht) {
            // remove the logger entry and inside all its parents reference
            logger = (Logger) ht.remove(key);
            if (logger != null) {
                String parentLogger = null;
                while ((parentLogger = getParentLogger(name)) != null) {
                    key = categoryKeyConstructor.newInstance(parentLogger);
                    Vector categoryEntries = (Vector) ht.get(key);
                    categoryEntries.remove(logger);
                    if (categoryEntries.isEmpty()) {
                        // remove the parent category if empty
                        ht.remove(key);
                    }
                    name = parentLogger;
                }
            }
        }
    } catch (Exception e) {
        logger.warn("Unable to access Log4J logger table, logger removal will be disabled", e);
    }
}